Database classes#

Combustion Toolbox generates its own databases using an up-to-date version of NASA’s 9-coefficient polynomial fits [McBride, 2002]. This information is stored in the Database abstract class. Three main databases are used in the code:

NasaDatabase: contains data extracted from NASA’s database [McBride, 2002].
BurcatDatabase: extracts data from the Third Millennium database [Burcat and Ruscic, 2005].
SolarAbundances: stores the solar abundances of the elements [Asplund et al., 2009].

Database#

class Database(varargin)#

Bases: handle

The Database abstract class contains the common methods between database objects. This class is used as a base class for the NasaDatabase and BurcatDatabase classes.

See also: NasaDatabase(), BurcatDatabase()

Database(varargin)#: Constructor

addSpecies(speciesName, DB_master)#: Add species to the database

extrapolationMethod = None#: Extrapolation method for the griddedInterpolant objects

filename = None#: Database filename

getProperty(listSpecies, property)#

Gets the vector of the defined property for the given set of species

Parameters:

obj (Database) – Database with custom thermodynamic polynomials functions generated from NASAs 9 polynomials fits
listSpecies (cell) – List of species
property (char) – Property name

Returns:

value (float) – Property vector

Example

value = getProperty(obj, {‘H2O’, ‘CO2’}, ‘hf’)

interpolationMethod = None#: Interpolation method for the griddedInterpolant objects

load(varargin)#

Load database from file

Parameters:: obj (Database) – Database object

Optional Args:: filename (char): Filename of the database

Returns:: obj (Database) – Database object

name = None#: Database name

pointsTemperature = None#: Number of points to use in the interpolation of the thermodynamic data

save()#

Save database to a *.mat file

Parameters:: obj (Database) – Database object

species = None#: Struct with Species objects

temperatureReference = None#: Default temperature of reference

thermoFile = None#: Name with path for the thermodynamic database file (raw data)

units = None#: Units thermodynamic data [molar or mass]

NasaDatabase#

class NasaDatabase(varargin)#

Bases: combustiontoolbox.databases.Database, handle

The NasaDatabase() class is used to store thermodynamic data from NASA’s database using NASA’s 9 coefficient polynomial fits.

The NasaDatabase() object can be initialized as follows:

database = NasaDatabase()

This creates an instance of the NasaDatabase() class and initializes it with the chemical species contained in NASA’s database.

See also: BurcatDatabase(), Database()

NasaDatabase(varargin)#

Constructor

Optional Args:: varargin (optional): key-value pairs to initialize the database

Returns:: obj (NasaDatabase) – Object with NASA’s database

Examples

db = combustiontoolbox.databases.NasaDatabase();
db = combustiontoolbox.databases.NasaDatabase(‘filename’, ‘DB.mat’);

static fullname2name(species)#

Get full name of the given species

Parameters:: species (char) – Chemical species
Returns:: name (char) – Full name of the given species

generateDatabase(varargin)#

Generate Database with thermochemical interpolation curves from the data extracted from the thermoFile

Parameters:: obj (NasaDatabase) – NasaDatabase object

Optional Args:

listSpecies (cell): List of species to generate the database

Returns:: obj (NasaDatabase) – NasaDatabase object with thermochemical interpolation curves

Examples

DB = generateDatabase(NasaDatabase());
DB = generateDatabase(NasaDatabase(), {‘N2’, ‘O2’, ‘NO’, ‘O’, ‘N’});

generateDatabaseMaster()#

Generate Master Database (DB_master) with the thermodynamic data of the chemical species

Parameters:: obj (NasaDatabase) – NasaDatabase object
Returns:: DB_master (struct) – Database with the thermodynamic data of the chemical species

Example

DB_master = generateDatabaseMaster(‘thermo_CT.inp’)

static getChangeMolesGasReaction(elements, elementMatrix, phase)#

In order to compute the internal energy of formation from the enthalpy of formation of a given species, we must determine the change in moles of gases during the formation reaction of a mole of that species starting from the elements in their reference state.

Notes

The only elements that are stable as diatomic gases are elements 1 (H), 8 (N), 9 (O), 10 (F), and 18 (Cl). The remaining elements that are stable as (monoatomic) gases are the noble gases He (3), Ne (11), Ar (19), Kr (37), Xe (55), and Rn (87), which do not form any compound.

Parameters:

elements (Elements) – Elements object
elementMatrix (float) – Element matrix of the species
phase (float) – 0 or 1 indicating gas or condensed species

Optional Args:

elements (Elements): Elements object

Returns:: Delta_n (float) – Change in moles of gases during the formation reaction of a mole of that species starting from the elements in their reference state

Example

Delta_n = getChangeMolesGasReaction(elements, element_matrix, phase)

static getCoefficients(species, DB)#

Unpack NASA’s polynomials coefficients from database

Parameters:

species (char) – Chemical species
DB (struct) – Database with custom thermodynamic polynomials functions generated from NASAs 9 polynomials fits

Returns:

Tuple containing

a (cell): Temperature coefficients
b (cell): Integration constants
Trange (cell): Ranges of temperatures [K]
Texponents (cell): Exponent coefficients
Tintervals (float): Number of intervals of temperatures
phase (float): 0 or 1 indicating gas or condensed phase, respectively
hf0 (float): Enthalpy of formation [J/mol]
W (float): Molecular weight [kg/mol]
FLAG_REFERENCE (bool): Flag indicating species is a reference element/species

Example

[a, b, Trange, Texponents, Tintervals, phase, hf0, W, FLAG_REFERENCE] = getCoefficients(‘H2O’, DB)

getDatabaseMaster(thermoFile)#

Generate Master Database (DB_master) with the thermodynamic data of the chemical species

Parameters:: thermoFile (char) – path of thermoFile
Returns:: DB_master (struct) – Database with the thermodynamic data of the chemical species

static getIndexTempereratureInterval(species, T, DB)#

Get interval of the NASA’s polynomials from the Database (DB) for the given species and temperature [K].

Parameters:

species (char) – Chemical species
T (float) – Temperature [K]
DB (struct) – Database with custom thermodynamic polynomials functions generated from NASAs 9 polynomials fits

Returns:

Tinterval (float) – Index of the interval of temperatures

getSpeciesThermo(DB, species, temperature, units)#

Calculates the thermodynamic properties of any species included in the NASA database

Parameters:

DB (struct) – Database with custom thermodynamic polynomials functions generated from NASAs 9 polynomials fits
species (char) – Chemical species
T (float) – Temperature [K]
units (char) – Label indicating mass [kg] or molar [mol] units

Returns:

Tuple containing

cP0 (float): Specific heat at constant pressure [J/(mol-k)]
hf0 (float): Enthalpy of formation [J/mol]
h0 (float): Enthalpy [J/mol]
ef0 (float): Internal energy of formation [J/mol]
s0 (float): Entropy [J/(mol-k)]
Dg0 (float): Gibbs energy [J/mol]

Example

[cp0, hf0, h0, ef0, s0, g0] = getSpeciesThermo(obj, DB, ‘CO’, 1000, ‘molar’)
cp0 = 33.1788
hf0 = -1.1054e+05
h0 = -8.8848e+04
ef0 = -1.1177e+05
s0 = 234.5409

getSpeciesThermoFull(DB, species, temperature, units)#

Compute thermodynamic function using NASA’s 9 polynomials

Parameters:

species (char) – Chemical species
temperature (float) – Range of temperatures to evaluate [K]
DB (struct) – Database with custom thermodynamic polynomials functions generated from NASAs 9 polynomials fits
units (char) – Label indicating mass [kg] or molar [mol] units

Returns:

Tuple containing

cp (float): Specific heat at constant pressure in units basis [J/(units-K)]
cv (float): Specific heat at constant volume in units basis [J/(units-K)]
h0 (float): Enthalpy in units basis [J/units]
DhT (float): Thermal enthalpy in units basis [J/units]
e0 (float): Internal energy in units basis [J/units]
DeT (float): Thermal internal energy in units basis [J/units]
s0 (float): Entropy in units basis [J/(units-K)]
g0 (float): Gibbs energy in units basis [J/units]

Example

[cp, cv, h0, DhT, e0, DeT, s0, g0] = speciesThermoFull(‘H2O’, 300:100:6000, DB)

species_DeT_NASA(species, temperature, DB)#

Compute thermal internal energy [J/mol] of the species at the given temperature [K] using NASA’s 9 polynomials

Parameters:

species (char) – Chemical species
temperature (float) – Range of temperatures to evaluate [K]
DB (struct) – Database with custom thermodynamic polynomials functions generated from NASAs 9 polynomials fits

Returns:

DeT (float) – Thermal internal energy in molar basis [J/mol]

Example

DeT = species_DeT_NASA(‘H2O’, 300:100:6000, DB)

species_DhT_NASA(species, temperature, DB)#

Compute thermal enthalpy [J/mol] of the species at the given temperature [K] using NASA’s 9 polynomials

Parameters:

species (char) – Chemical species
temperature (float) – Range of temperatures to evaluate [K]
DB (struct) – Database with custom thermodynamic polynomials functions generated from NASAs 9 polynomials fits

Returns:

DhT (float) – Thermal enthalpy in molar basis [J/mol]

Example

DhT = species_DhT_NASA(‘H2O’, 300:100:6000, DB)

species_cP_NASA(obj, species, temperature)#

Compute specific heats at constant pressure and at constant volume [J/(mol-K)] of the species at the given temperature [K] using NASA’s 9 polynomials

Parameters:

obj (NasaDatabase) – NasaDatabase object
species (char) – Chemical species
temperature (float) – Range of temperatures to evaluate [K]

Returns:

Tuple containing

cp (float): Specific heat at constant pressure in molar basis [J/(mol-K)]
cv (float): Specific heat at constant volume in molar basis [J/(mol-K)]

Example

[cp, cv] = species_cP_NASA(‘H2O’, 300:100:6000, DB)

species_cV_NASA(species, temperature, DB)#

Compute specific heat at constant volume [J/(mol-K)] of the species at the given temperature [K] using NASA’s 9 polynomials

Parameters:

species (char) – Chemical species
temperature (float) – Range of temperatures to evaluate [K]
DB (struct) – Database with custom thermodynamic polynomials functions generated from NASAs 9 polynomials fits

Returns:

cV (float) – Specific heat at constant volume in molar basis [J/(mol-K)]

Example

cV = species_cV_NASA(‘H2O’, 300:100:6000, DB)

species_e0_NASA(species, temperature, DB)#

Compute internal energy and the thermal internal energy [J/mol] of the species at the given temperature [K] using NASA’s 9 polynomials

Parameters:

species (char) – Chemical species
temperature (float) – Range of temperatures to evaluate [K]
DB (struct) – Database with custom thermodynamic polynomials functions generated from NASAs 9 polynomials fits

Returns:

Tuple containing

e0 (float): Internal energy in molar basis [J/mol]
DeT (float): Thermal internal energy in molar basis [J/mol]

Example

[e0, DeT] = species_e0_NASA(‘H2O’, 300:100:6000, DB)

species_g0_NASA(obj, species, temperature)#

Compute Compute Gibbs energy [J/mol] of the species at the given temperature [K] using NASA’s 9 polynomials

Parameters:

obj (NasaDatabase) – NasaDatabase object
species (char) – Chemical species
temperature (float) – Range of temperatures to evaluate [K]

Returns:

g0 (float) – Gibbs energy in molar basis [J/mol]

Example

g0 = species_g0_NASA(NasaDatabase(), ‘H2O’, 300:100:6000)

species_gamma_NASA(species, T, DB)#

Compute adiabatic index of the species [-] at the given temperature [K] using piecewise cubic Hermite interpolating polynomials and linear extrapolation

Parameters:

species (char) – Chemical species
T (float) – Range of temperatures to evaluate [K]
DB (struct) – Database with custom thermodynamic polynomials functions generated from NASAs 9 polynomials fits

Returns:

gamma (float) – Adiabatic index [-]

Example

gamma = species_gamma_NASA(‘H2O’, 300:100:6000, DB)

species_h0_NASA(species, temperature, DB)#

Compute enthalpy and thermal enthalpy [kJ/mol] of the species at the given temperature [K] using NASA’s 9 polynomials

Parameters:

species (char) – Chemical species
temperature (float) – Range of temperatures to evaluate [K]
DB (struct) – Database with custom thermodynamic polynomials functions generated from NASAs 9 polynomials fits

Returns:

Tuple containing

h0 (float): Enthalpy in molar basis [J/mol]
DhT (float): Thermal enthalpy in molar basis [J/mol]

Example

[h0, DhT] = species_h0_NASA(‘H2O’, 300:100:6000, DB)

species_s0_NASA(species, temperature, DB)#

Compute entropy [J/(mol-K)] of the species at the given temperature [K] using NASA’s 9 polynomials

Parameters:

species (char) – Chemical species
temperature (float) – Range of temperatures to evaluate [K]
DB (struct) – Database with custom thermodynamic polynomials functions generated from NASAs 9 polynomials fits

Returns:

s0 (float) – Entropy in molar basis [J/(mol-K)]

Example

s0 = species_s0_NASA(‘H2O’, 300:100:6000, DB)

species_thermo_NASA(species, temperature, DB)#

Compute thermodynamic function using NASA’s 9 polynomials

Parameters:

species (char) – Chemical species
temperature (float) – Range of temperatures to evaluate [K]
DB (struct) – Database with custom thermodynamic polynomials functions generated from NASAs 9 polynomials fits

Returns:

Tuple containing

cP (float): Specific heat at constant pressure in molar basis [J/(mol-K)]
cV (float): Specific heat at constant volume in molar basis [J/(mol-K)]
h0 (float): Enthalpy in molar basis [J/mol]
DhT (float): Thermal enthalpy in molar basis [J/mol]
e0 (float): Internal energy in molar basis [J/mol]
DeT (float): Thermal internal energy in molar basis [J/mol]
s0 (float): Entropy in molar basis [J/(mol-K)]
g0 (float): Gibbs energy in molar basis [J/mol]

Example

[cP, cV, h0, DhT, e0, DeT, s0, g0] = species_thermo_NASA(‘H2O’, 300:100:6000, DB)

BurcatDatabase#

class BurcatDatabase(varargin)#

Bases: combustiontoolbox.databases.Database, handle

The BurcatDatabase() class is used to store thermodynamic data from Burcat’s database using NASA’s 9 coefficient polynomial fits.

The BurcatDatabase() object can be initialized as follows:

database = BurcatDatabase()

This creates an instance of the BurcatDatabase() class and initializes it with the chemical species contained in Burcat’s database.

See also: NasaDatabase(), Database()

BurcatDatabase(varargin)#: Constructor

static thermoMillennium_2_thermoNASA9(filenameInput, varargin)#

Read Extended Third Millennium Thermodynamic Database of New NASA Polynomials with Active Thermochemical Tables update and write a new file compatible with thermo NASA 9 format

Parameters:

filenameInput (char) – Filename of the thermoMillennium data
filenameOutput (char) – Filename of the thermoMillennium data as NASA9

SolarAbundances#

class SolarAbundances(varargin)#

The SolarAbundances class is used to read solar abundances and compute the initial molar composition of the mixture